Solar WXLink LoRa - Wireless Data Link designed for the WeatherRack and the WeatherBoard

Solar WXLink LoRa - Wireless Data Link designed for the WeatherRack and the WeatherBoard - Grove

NOTE: The unit is shipped with a simple wire antenna on each LoRa transceiver. This is good (depending on your environment, walls, etc) to about 30m. Above 30m you may want to consider another antenna(although test it first. You may be OK!) such as ourYagi Antenna. You can add a Yagi at both ends to really blow out the range. 6000 meters or even further depending on the height of the antenna and environment. You need to try it and see.

What is the Solar WXLink LoRa?

The Solar WXLink is a solar powered wireless serial link that can transmit up to 6000 meters in free air, with the proper antenna (like our Yagi Antenna product). It is designed to connect up to any source of data from sensors connected to the Mini Pro LP Arduino compatible low power computer board. It was specifically designed to connect a WeatherRack weather sensor array to a Weather Board based system connected to an Arduino or Raspberry Pi computer. The receiver is read by the host computer through an I2C interface. Much easier and more available than a serial interface. And yes, it has Grove connectors throughout the system. The WXLink LoRa comes preloaded with the software to support a WeatherRack and AM2315. See below for the source code. No soldering required.

This design uses SunAirPlus which collects (and transmits the information back to the weather station) information on the power system (Solar Panel Voltage/Current, Load Voltage/Current, Battery Voltage/Current). A GREAT science project! Lots of data.

The serial link is bi-Directional although the software currently just supports a uni-directional link.

(Note: The second Solar Panel is for those locations with more than average cloud cover. It is optional to install. If you wish to install it, you will need to solder two wires from the positive (+) on one solar panel to the positive (+) on the other panel and the negative (-) on one solar panel to the negative (-) on the second panel as in the picture below.).

Downloads

Wiring Diagram

One of the inspirations for the WXLink LoRa was the previous kickstarter we did, "The Weather Board for the Raspberry Pi". One of the devices that the Weather Board connects to is the SwitchDoc Labs WeatherRack wind and rain sensor.

WeatherRack Wind and Rain Sensor

The issue is sometimes you don't want to run a wire all the way from the Weather Station to the wind and rain sensor. Like all the time. So, using the Mini Pro LP, we build a solar powered WeatherRack reader and then we use a transmitter to send it back to the station inside the lab. Did it on an average power of less than 5mA which made solar power easy to add. No power. No wires. More on this project in the next few weeks. Here is the complete project on a walkabout near the Spokane river. 433 meter (1,473 feet) range. Amazing for a little solar powered device! With a good antenna (like our Yagi Antenna), you can go 6000m.

Solar Powered Mini Pro LP on a Walkabout. We have now boxed up the WXLink and it is out in the Sun. Running perfectly.

Below is a picture of the Solar version of the WXLink.

Results

We have been running the Mini Pro LP on solar power for over a week now. It is working perfectly for 5 days now. Not a single reboot. We have an external WatchDog Timer (see tutorial: http://www.switchdoc.com/2014/11/reliable-projects-watchdog-timers-raspberry-pi-arduinos/ ) installed to protect the system from brownouts (which we tested before we took the system outside). The data is great. This graph shows two days (captured by the Rx part of the WXLink with Mini Pro LP) and using the Raspberry Pi Datalogger to store and generate graphs (see tutorial: http://www.switchdoc.com/2016/06/datalogger-measuregraphlog-current-raspberry-pi/ ). You can see from these graphs the the battery on board is fully charged (when that happens SunAirPlus turns the charging circuitry off to protect the battery and the solar panel voltage climbs from 5V to about 7V. It turns on a bit during the day when the battery has discharged a bit again. The data from the last message is shown below the graph.

Latest Data

This data is from the Raspberry Pi DataLogger reading the WXLink. Block diagram and description below.